This invention relates to passive components integrated on an integrated circuit chip, an integrated circuit carrier, and a circuit board.
This invention also relates to low capacitance multilayer circuit boards, to interconnect structures for high speed microprocessors, to application specific integrated circuits (ASICs), and to other high speed integrated circuits (IC""s).
The structures of this invention include a dielectric material having a low dielectric constant, very high breakdown field, and excellent (air barrier) passivation properties.
The invention also describes an improved thin film form of the dielectric material that is useful in some of the inventive electronic structures.
Prior art inductor structures used in RF and microwave circuits are commonly isolated from ground using SiO2 which has a dielectric constant (k) of 4 to 4.2. Prior art inductors may be passivated with a polymer dielectric (e.g. Polyimide) which has a dielectric constant (k) or about 2.9.
Prior art transformer structures are commonly isolated internally using SiO2 with a dielectric constant (k) of 4 to 4.2 between adjacent conductors or turns in the winding and between windings.
Prior art multilayer circuit boards commonly are built with a polymer dielectric that absorbs water and has a relatively low breakdown field.
A multilayer circuit board structure is needed with low capacitance between metal layers, such as using a dielectric material with a low dielectric constant, a high breakdown voltage and very low water absorption.
In the prior art, Cu interconnect structures with low-k dielectric are known. An example dual damascene type structure is described in R. Goldblatt et al, xe2x80x9cA high performance 0.13 micron Copper BEOL technology with low k dielectricxe2x80x9d, Proceedings of IITC, 2000. These structures may have high leakage current between the Cu lines, especially as the spacing between the lines is reduced below 180 nm.
Prior art capacitor structures used in RF and microwave circuits are commonly isolated from ground using SiO2 which has a dielectric constant (k) of 4 to 4.2, or another material with still larger k. The capacitors may be passivated with a polymer dielectric (e.g. Polyimide) which has a dielectric constant (k) or about 2.9.
U.S. Pat. No. 6,147,009 by Grill et al. which issued Nov. 14, 2000 entitled xe2x80x9cHydrogenated Oxidized Silicon Carbon Materialxe2x80x9d describes SiCOH dielectric material and is assigned to the assignee herein which is incorporated herein by reference.
U.S. Pat. No. 6,312,793 by Grill et al. which issued Nov. 6, 2001 describes a multiphase low dielectric constant material and is assigned to the assignee herein which is incorporated herein by reference.
U.S. Pat. No. 5,095,357 by Andoh et al. which issued Mar. 10, 1992 entitled xe2x80x9cInductive Structures For Semiconductor Integrated Circuitsxe2x80x9d describes inductive structures which is incorporated herein by reference.
U.S. Pat. No. 5,773,870 by Su et al. which issued Jun. 30, 1998 entitled xe2x80x9cMembrane Type Integrated Inductor And The Process Thereofxe2x80x9d describes and inductor which is incorporated herein by reference.
U.S. Pat. No. 5,793,272 by Burghartz et al. which issued Aug. 11, 1998 entitled xe2x80x9cIntegrated Circuit Toroidal Inductorxe2x80x9d describes both toroidal and spiral inductors which is assigned to the assignee herein and which is incorporated herein by reference.
The invention provides electronic structures that have superior properties, i.e. reduced parasitic capacitance and improved reliability. The structures of this invention contain a dielectric material xe2x80x9cSiCOHxe2x80x9d having a low dielectric constant, very low leakage current, high breakdown field, and excellent passivation (air barrier) properties.
Various inductive and capacitive structures with superior electrical performance are disclosed. All of the structures have reduced parasitic capacitance (reduced capacitive coupling to a supporting substrate), compared to prior art structures using existing dielectrics. Reduced parasitic capacitance (reduced capacitive coupling to a substrate) results in Lower Power consumption and higher frequency performance.
Included are inductors having reduced capacitance both within the inductive device and parasitic capacitance between the device and ground, transformers having reduced capacitance within the device, low capacitance circuit boards, and reliable capacitors having a low capacitance.
The invention provides a spiral, toroidal or membrane inductor having a low capacitance within the inductive structure, and a low capacitance between the inductor and ground. In addition, these inductors must be reliable for long life in integrated circuits such as in mobile applications. These properties are obtained in an inductor structure containing SiCOH dielectric material having a low dielectric constant, a high breakdown voltage, a low leakage current, and low oxygen and water permeation to isolate the inductor from the substrate.
The invention provides a transformer having a low internal capacitance between two conductive windings. Also, the transformer should have a low capacitance to the substrate or ground. In addition, the transformer must be reliable. These properties are obtained in a transformer containing a layer of SiCOH dielectric material between the 2 windings. Said SiCOH dielectric has a low dielectric constant, a high breakdown voltage, a low leakage current, and low oxygen and water permeation.
An improved low-k dielectric plus Cu interconnect structure (such as dual damascene type) for high speed microprocessors and ASIC""s according to the invention is also described.
The invention provides a low-k Cu interconnect structure with a dielectric having a low dielectric constant (k) and simultaneously a low leakage current between Cu lines where the lines are spaced less than 180 nm apart.
It is an object of this invention to provide reliable capacitors (with a low, stable capacitance), inductors having reduced capacitance within the inductive device and a reduced parasitic capacitance between the device and ground, low capacitance circuit boards, and an improved low-k dielectric plus Cu interconnect structure (such as dual damascene type).
The invention provides an interdigital capacitor having a low parasitic capacitance and excellent reliability. This is obtained in a capacitor structure in which the SiCOH dielectric material has a low dielectric constant, a high breakdown voltage, a low leakage current, and low oxygen and water permeation, is used to isolate the structure from the substrate.
It is another object of this invention to utilize a dielectric material comprised of Si, C, O, and H (called xe2x80x9cSiCOHxe2x80x9d) which has a dielectric constant of less than 3.5 and a high breakdown field, greater than 4.5 MV/cm, and a low leakage current in the inventive structures. A low leakage current is defined here as approximately less than 10 nAmp/cm2 at an applied field of 1 MV/cm. Further, this material is a reliable barrier to O2 and H2O permeation.
This invention improves on prior art structures by reducing the parasitic capacitance of the structures.
The integrated devices also have excellent electrical isolation (low leakage).
Both of these reduce the power consumption of the structures.
As described herein, the SiCOH dielectric material (also called xe2x80x9ccarbon-doped oxidexe2x80x9d) exhibits a very high breakdown voltage, from 4.5 to 10 MV/cm, and a low leakage current and dielectric constant less than 3.5 when prepared according to the procedures described here and when the material has the atomic composition specified herein.